Daikin DBG Series, Service Instructions Manual

Page: 12 / 108

SYSTEM OPERATION
12
GAS SUPPLY PIPING
T
O PREVENT PERSONAL INJURY OR DEATH DUE TO IMPROPER
INSTALLATION
,
ADJUSTMENT
,
ALTERATION
,
SERVICE OR MAINTENANCE
,
REFER TO THIS MANUAL
. F
OR ADDITIONAL ASSISTANCE OR
INFORMATION
,
CONSULT A QUALIFIED INSTALLER
,
SERVICE AGENCY OR
THE GAS SUPPLIER
.
WARNING
IMPORTANT NOTE: This unit is factory set to operate on
natural gas at the altitudes shown on the rating plate.
T
O PREVENT PROPERTY DAMAGE
,
PERSONAL INJURY OR DEATH WHEN
EITHER USING PROPANE GAS ALONE OR AT HIGHER ALTITUDES
,
OBTAIN
AND INSTALL THE PROPER CONVERSION KIT
(
S
). F
AILURE TO DO SO CAN
RESULT IN UNSATISFACTORY OPERATION AND
/
OR EQUIPMENT DAMAGE
.
H
IGH ALTITUDE KITS ARE FOR
U.S. I
NSTALLATIONS ONLY AND ARE NOT
APPROVED FOR USE IN
C
ANADA
.
WARNING
The rating plate is stamped with the model number, type of
gas and gas input rating. Make sure the unit is equipped to
operate on the type of gas available. Conversion to propane
(LP) gas is permitted with the use of the factory authorized
conversion kit (see the unit Spec Sheet Manual for the appro-
priate kit). For High Altitude derates, refer to the latest edition
of the National Fuel Gas Code NFPA 54/ANSI Z223.1.
NATURAL Min. 5.0" W.C., Max. 10.0" W.C.
PROPANE Min. 11.0" W.C., Max. 14.0" W.C.
INLET GAS PRESSURE
Inlet Gas Pressure Must Not Exceed the Maximum Value Shown in Table
Above.
The minimum supply pressure should not vary from that
shown in the table above because this could prevent the unit
from having dependable ignition. In addition, gas input to the
burners must not exceed the rated input shown on the rating
plate. Overfiring of the unit could result in premature heat
exchanger failure.
Piping
IMPORTANT NOTE: To avoid possible unsatisfactory opera-
tion or equipment damage due to under firing of equipment,
do not undersize the natural/propane gas piping from the
meter/tank to the unit. When sizing a trunk line, include all
appliances on that line that could be operated simultaneously.
The rating plate is stamped with the model number, type of
gas and gas input rating. Make sure the unit is equipped to
operate on the type of gas available. The gas line installation
must comply with local codes, or in the absence of local codes,
with the latest edition of the National Fuel Gas Code NFPA
54/ANSI Z223.1.
Natural Gas Connection
1/2 3/4 1 1 1/4 1 1 /2
10 132 278 520 1050 1600
20 92 190 350 730 1100
30 73 152 285 590 980
40 63 130 245 500 760
50 56 115 215 440 670
60 50 105 195 400 610
70 46 96 180 370 560
80 43 90 170 350 530
90 40 84 160 320 490
100 38 79 150 305 460
Pressure= .50 PSIG or less and Pressure Drop of 0.3" W.C.
(Based on 0.60 Specific Gravity Gas)
Natural Gas Capacity of Pipe
in Cubic Feet of Gas Per Hour (CFH)
Nominal Black Pipe Size (inches)
Length of
Pipe in Feet
Heating Value of Gas (BTU/Cubic Foot
CFH =
BTUH Furnace Input
Refer to the Proper Piping Practice drawing for the general
layout at the unit. The following rules apply:
1. Use black iron pipe and fittings for the supply piping. The
use of a flex connector and/or copper piping is permitted
as long as it is in agreement with local codes.
2. Use pipe joint compound on male threads only. Pipe joint
compound must be resistant to the action of the fuel used.
3. Use ground joint unions.
4. Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum of
three inches long.
5. Use two pipe wrenches when making connection to the
gas valve to keep it from turning.
6. Install a manual shut-off valve in a convenient location
(within six feet of unit) between the meter and the unit.
7. Tighten all joints securely.
8. The unit must be connected to the building piping by one
of the following methods:
• Rigid metallic pipe and fittings
• Semirigid metallic tubing and metallic fittings (Aluminum
alloy tubing must not be used in exterior locations)
• Listed gas appliance connectors used in accordance with
the terms of their listing that are completely in the same
room as the equipment
• In the prior two methods above the connector or tubing
must be protected from physical and thermal damage.
Aluminum alloy tubing and connectors must be coated
to protect against external corrosion when in contact with
masonry, plaster or insulation or are subject to repeated
wettings by liquids (water - not rain water, detergents or
sewage).